Art of making wax patterns for castings for dental work.



A. W. TATHAM. ART OF MAKING WAX PATTERNS FOR GASTINGS FOR DENTAL WORK.

APPLICATION FILED APR.15, 1911'. 1,033,489.

Patented July 23, 1912.

A Zdnuvntpr w. t/azzfz Eimnuma double socket made of cast metal.

UNITED STATES PATENT OFFICE.

ARTHUR w. TATHAM, or DETROIT, MICHIGAN.

ART OF MAKING WAX PATTERNS FOR CASTINGS FOR DENTAL WORK.

Specification of Letters Patent.

Patented July 23, 1912.

i Application filed April 15, 1911. Serial No. 621,196.

To all whom it may concern:

Be it known that I, ARTHUR W. TATHAM, a citizen of the United States, residing at De-. troit, county of Wayne, State of Michigan, have invented a certain new and useful Improvement in the Art of Making Wax Patterns for Castings for Dental Work, and declare the following to be a full, clear, and exact description of the same, suchas will enable others skilledin the art to which it pertains to make and use the same, reference being had to the accompanying drawings, which form a part of this specification.

This invention relates to the art of making wax patterns for castings for dental work.

It has for its object an improved process of constructing the small wax patterns or images used by dentists in making castings,- generally castings of gold; for many pur' poses connected with the dental art.

For purposes of illustration, 1' have selected as samples of the work to be done in carrying out this process, the two forms shown in the accompanying drawings, in which Figure 1, shows a defective tooth prepared for repair by fixing thereto a filling Fig. 2, shows a piece of wire gauze used in the process. Fig. 3, shows a section of the same piece of wire gauzeas it is shaped in carry- .ing out the process. Fig. 4, shows a section of the same piece of wire "gauze. as it is finally shaped and coated with wax. Fig. 5, shows a natural base or root to which is attached an artificial crown by means of a Fig. 6, showsthe double socket used in Fig. 5. Fig. 7 is a cross section showing a root member, an artificial crown member, and the double socket by which the two are united.

To illustrate the process and the character of the pattern that is produced by carrying out the process, suppose a teeth 1 is tobe provided with-a filling that partially covers the crown; in producing such a filling there is employed a piece of wire gauze 2 which is usedas a reinforcing member in the pattern A. Toillustrate a difierentoperation suppose a natural root 7 of a tooth is to have.

joined to it an artificial crown 8 by' a metal connecting. member in which there are opposed sockets contained withinthe rings 9 and 10 and joined by a metal connection 11;

gages over the root 7 and the other of which engages under the crown 8 and which is cemented to both the root and the crown.

These two illustrative structures show only a few of the many structures for which the complete pattern produced by the process about to be. described maybe used, but these are sufiicient, it is thought, to fully explain .the process and make evident the range of use of the process. v

In carrying out the process the tooth to be treated is cleaned, decayed parts cut away, and such provision as is best adapted for the special case is made that the tooth, or portion of the tooth shall be intimately connected to and shall securely hold the casting that is to be made and ,placed upon it, or within the cavity in it. After the preparatory work is done a small piece of thin metal-preferably wire gauze of .very fine mesh is laid over that part of the tooth to which the casting is to conform. The metalv or'mesh is crowded and pressed into close engagement with thejsurface of the tooth, burnished along the edges of the metal, turning the metal over the edge and cavity, or

the edges of the tooth as the case may be, and fitting it as closely thereto as it can be conveniently. After this fitting a coating of wax is placed over the partly formed mesh and the wax coated mesh is removed from the tooth; a coating of wax is placed onthe under side of it and the form is' again crowded to its place on the tooth .or in'the cavity crowding out superfluous wax from underneath it and crowding the wax more intimately into the sinuosities of the cavity.

The now partially completed pattern is re' moved from the tooth, the edges oft-he wire gauze clipped ofi' with scissors until the projecting edges are trimmed away. The partly,

finished pattern is replaced in the cavity or on the tooth and the wax is pressed and worked entirely over the edges of the metalusing aburnishing tool or some similar implement and warming the tool if necessary. v

The extremeedge of the pattern 1s made very thin, sometimes so thin that it scarcely equals the five one-thousandths of aninch (the wire gauze used may be as thin as four one-thousandths of an inch in thickness). When the pattern has been fully shaped-it is again removed from the tooth and covered with investing material in the ordinary way of making amold. The further treatment is quite similar to the treatment of the ordinary wax patterns used in the art; after the pattern has been placed in the flask and the arrangements for the sprue' perfected the wax is removed by melting it out from the mold leaving the metal gauze suspended in the mold. The molten gold is then poured into the mold and the metal gauze becomes a part of the final casting, it disappears as a mesh, but remains as a metal.

In carrying out. this process, the pattern may be removed and replaced as often as may be necessary. It can be very easily removed because the adhesion of the wax to the included strengthening metal so much exceeds the adhesion of the wax to the tooth being treated, thatthe pattern may be re- .moved without distorting even the thinnest edges of theparts, and when removed may be handled readily without danger of injuring even the thinnest edges, and the facility of removing and replacing enables it to be shaped and formed on both its at taching side and its free side exactly as ma; be desired or required. For example, if t be desired to close the teeth upon the partially finished pattern in order to shape the pattern to-co'rrespond with the opposing tooth in the jaw,;or if it be desired to close the teeth on a crown, such as is shown in Fig. 5, in order to get the proper shape and proper length of t e projection of the crown, this may be done without fear of injury to the pattern itself. The process can be used for the production of a tie member to hold an artificial crown to a natural root, such as is shown in Fig. 6, by making a reinforced form in connection wit-h the root member and another reinforced form in connection with the crown member, which two reinforced forms are held together by an intermediate layer of wax, the complete pattern consists in this instance, of two reinforcing members embedded in a unitary mass of wax, and one part of the pattern is adapted to engage over the root, and another part of the pattern is adapted .to engage the artificial crown; these are formed with great accuracy to engage closely and entirely around the root and crown; the pattern is very thin at its edges and does not present a thick band around either part and yet it -has 'reat firmness and preserves its shape and integrityduring the period of manipu- 1 lation and'the gauze is held in the mold ac-i curately after the wax is melted out. The casting made from this pattern comprises a cup part 9 and a cup part 10 joined by metal connection 11 and of these the cup part 9 is adapted to engage and inthe completed work doesengage closely over the root 7 oft-he tooth and thecup shaped part 10 is adapted to engage, and the finished 65 work does engage closely and accurately .characters of work.

around the under part of the crown 8 and the two cup shapedparts are joined by the solid metal part 11.

The pin; 12 is used in the ordinary way as an anchor, or it may be omitted in many It is evident that this process may be used in all dental work where it is desirable to join a metal piece to the natural part of the tooth, Whether the metal piece itself be a finishing piece or a'mere union piece between the root a'ndthe artificial part of the tooth that is connected to the root. It is also evident that the same process may be used to. great advantage in work Where all the parts to be connected are artificial, and its uses in out-of-the-mouth dentistry may be just as great as its. uses in in-the-mouth dentistry. Q

In casting the final form to correspond to the pattern, the usual and well known method of packing the pattern in the mold material and the formatlon of spruce is followed out in the well known way of casting.

In making large gold work, the gold may be cast over a cage made from the gauze in which is included a core of any suitable material used to avoid expense and weight; in such work the cage while yet unfilled may be'shaped as desired and the core is afterward placed in and closed entirely in.

a What I claim is 1. The process of producing a pattern for dental purposes, comprising a preparation of the part to which the pattern is to conform, placing over the'part a piece of gauze, shaping the gauze to conform roughly to the part, coating the shaped gauze on both" sides with wax, again shaping the waxed metal to conform to the part, 1057 trimming ofl superfluous gauze around the edges, and giving a final shape to the external surface of the waxed gauze, substantially as described.

2. The process'of producing a pattern for dental purposes, comprising the placing over the part to which the pattern is to conform apiece of gauze, shaping the gauze to conform roughly to the part, coating the shaped gauze with wax, shaping the 5 waxed gauze to conform to the part, sub stantially as described.

3. The process of producing-a pattern for dental purposes, comprising the placing over the part to which the pattern is to conform apiece of gauze, shaping the gauze to conform roughly to the part, coating the .shaped gauze with wax, shaping the waxed gauze to conform to the part, embedding the same in a porous heat-resisting m0ld'125 and applying heat to melt, and absorb the wax, substantially as described.

4. The process of producing a patternfor dental purposes,'comprising the shaping of a metal reinforcing base to correpattern, substantially as described.

5. The process of producing a pattern for dental purposes, comprising first the rough shaping of a piece of metallic plastic f0- raminiferous material to the part to which the pattern is to conform, finishing the shaping by adding thereto a non-metallic 10 plastic material to conform to the part re-, ferred to, substantially as described.

In testimony whereof, I sign this specification in the presence of two witnesses.

ARTHUR W. TATHAM. Witnesses:

, VIRGINIA O. SPRATT,

CHARLES F.' BURTON. 

